OS Therapies (NYSE: OSTX) is a cancer immunotherapy company engaged in the development of new treatments for osteosarcoma and other solid tumors. Headquartered in New York, the clinical-stage biopharmaceutical company is on a mission to develop the first new osteosarcoma treatment in over 30 years. In an email conversation with AplhaStreet, Paul Romness, president and chief executive officer of OS Therapies, spoke about the company’s mission and clinical programs.

How would you summarise the business of OS Therapies, and how your vision for the company has evolved since founding it?

We founded OS Therapies in 2018 specifically to address a rare, pediatric bone cancer, osteosarcoma, after being inspired to find a treatment after a personal connection battled the disease.

This is still a main focus for us and we are actively advancing OST-HER2, our immunotherapy candidate for the prevention of recurrence of metastases in osteosarcoma. As time has evolved, we have also begun to see our immunotherapy and ADC (Drug Conjugates) platforms as potential new treatments for many other solid tumors. In February, we announced the formation of our subsidiary OS Drug Conjugates to create value from our leading-edge, patented silicone dioxide-based, pH-sensitive tunable antibody-drug conjugates (tADC) & other tunable drug conjugates (tDC) platform.

Could you elaborate on how OS Therapies plans to expand its clinical programs, from treating osteosarcoma to addressing other cancers like lung and ovarian cancer?

If we receive US FDA approval for OST-HER2 in osteosarcoma, we will be issued a Priority Review Voucher (PRV) currently worth $100-150 million, which we will use to further develop the immunotherapy OST-HER2 in other solid tumors.

Can you talk about the potential of OST-HER2 and OST-tADC technologies in transforming the treatment of various cancers, especially osteosarcoma?

OST-HER2 is an immunotherapy leveraging the immune-stimulatory effects of Listeria bacteria to initiate a strong immune response targeting the HER2 protein. It works by stimulating the immune system to produce killer T-cells (lymphocytes) that seek out and destroy micro-metastases before they can take hold in the lungs and brain. Earlier this year, we released positive Phase 2b data that demonstrate statistically significant results in the primary endpoint of the study, 12-month event-free survival (EFS).

Our OST-tADC platform seeks out large, bulky tumors that it attacks and debulks. It incorporates pH-sensitive silicon-based linkers, SiLinkers™, to link the targeting antibodies (or antibody fragments) and therapeutic moieties together while coating the entire package with pH-sensitive coating. This approach can release multiple therapeutic agents selectively within the tumor and tumor microenvironment, which have lower pH levels than the rest of the body. It aims to maximize the therapeutic effects while minimizing damage to healthy cells.

With the oncology and immunotherapy markets becoming increasingly competitive, what specific aspects of OS Therapies differentiate it from other players in this space?

Unmet medical needs have always been our primary goal, as osteosarcoma is rare and deadly. There have been no new treatments for osteosarcoma in 30 years and we are passionate about advancing one. We will always go to alternate targets with novel and innovative technology. Our team also has deep experience within the pharmaceutical, biotechnology, oncology, and immunology sectors, and is committed to our mission of revolutionizing cancer treatments and giving hope to those impacted by aggressive cancers.

Can you provide updates on the company’s therapeutic pipeline, and shed light on the main challenges to its clinical programs?

Our pipeline currently includes two therapeutics OST-HER2 and OST-tADC. OST-HER2 is for osteosarcoma, breast, esophageal, and colorectal cancer. OST-tADC is for ovarian, colorectal, and breast cancers.

Challenges to the clinical program are inherent in drug discovery and regulatory approval. We are applying globally for commercial approval from multiple regulatory bodies. And although many follow the same general process, we want to make sure our therapy is available for patients globally. This takes a very detailed and thorough process with multiple experts, working diligently to meet deadlines and protocols. And as challenging as this is, everyone on our extended team is absolutely dedicated to our patients, wherever they may be.